Many previous surveys of the rapid variability of Be stars (e.g., Balona et al. 1987, Cuypers et al. 1989, Balona et al 1992) were limited to the Strömgren b-band only. We have undertaken a new observational effort with the specific aim of studying colour variations. A search for new rapidly variable stars should provide us with statistical material needed to generalize properties of the phenomenon with respect to the stellar parameters. Some preliminary results of these items are presented here.